1. Field
The present invention relates to resource allocation in a wireless communication system, and more specifically to scheduling of transmissions to multiple users as a function of user historical information.
2. Background
Emerging high-speed data networks attempt to balance efficient resource allocation with the provision of fair service to a variety of users. Many variables complicate this balancing effort. For example, in many communication systems, users are provided a variety of service options. Those users that subscribe to higher premiums for faster connections expect to have priority over users that subscribe to lower premiums. Similarly, data rate requirements of the various services provided require the system to adapt to the actual usage as well as potential usage of the system at any given time. Further, packet transmissions are constrained to specified packet delay requirements in particular to real-time data users, such as in a broadcast transmission. Still further, optimization of the quality of service to each user is fundamental to maintaining users in a communication system. Quality of Service, or QoS, of a wireless channel is typically different for different users, and randomly changes with time.
As the use of portable computers, smart wireless phones, and personal digital assistants increase, the multimedia services demand will likely overwhelm the resources of current wireless networks. It is important to exploit all available information when considering ways to deliver the quality of service that end users expect. If the system knows that for the next few seconds the channel conditions is not favorable to send a specific data rate or there will be too many handoffs that consumes additional resources and hence does not transmit to the wireless device until conditions have improved. Here lies the tradeoff in which the scheduler must decide whether it is efficient to transmit to a particular wireless device even when that decision may decrease the instantaneous channel throughput. Efficient data scheduling techniques are designed to meet the various needs of resource allocation and fairness and minimize interference to other users. There are a variety of scheduling techniques and algorithms available to meet such needs. Most of these algorithms consider the currently pending data rate requests and the current channel conditions of the system. Developing a scheduling technique that responds to the condition of the current system incurs a delay, as the system controller must receive such information prior to making scheduling decisions. As the number of users desiring data services increases, such delays may negatively impact the quality of service of said system. In addition, knowing the usage patterns of wireless users one can design more efficient assignment strategies. For example, knowing the average hold time of data call for a user at specific times of the day can be used to influence the assignment strategy of the data bursts.
There is, therefore, a need in the art to allocate resources in a communication system and avoid part or all of the delay incurred by responding to the current state of a communication system and meantime minimize interference to other users. Still further, there is a need to use historical information to predict trends of usage and act a priori to the system state. Additionally, there is a need to predict a future condition of the system including the state of the communication channel(s), and available resources for application in scheduling algorithms. Furthermore, there is a need to utilize knowledge about usage patterns to develop efficient assignment strategies.